Connection for high voltage lines



Jan. 17, 1933. us'rm 1,894,338

CONNECTION FOR HIGH VOLTAGE LINES Filed Jan. 21, 1928 a Sheets-Sheet 1lln Y 5 x 1 a 9,? a U .\M M I J 5::

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Sm f f E I 23 E 3 5 0 l INVENTOR fi ATTORNEY Jan. 17, 1933. A. o. AUSTIN1 1,894,338

CONNECTION FOR HIGH VOLTAGE LINES Filed Jan. 21. 1928 a Sheets-Sheet 2UUUUU Vol/aye 0/1 L000.

ATTORNEY Fly/2' BY Jan. 17, 1933. A. o. AUSTIN CONNECTION FOR HIGHVOLTAGE LINES Filed Jan. 21, 1928 3 Sheets-Sheet 5 INVENTOR @L:ZM am Wed@040 ATTORNEY Patented Jan. 17, 1933 UNITED STATES PATENT OFFICE ARTHURO. AUSTIN, OF NEAR BABIBERTON, OHIO, ASSIGNOR, BY MESNE ASSIGNMENTS, TOTHE OHIO BRASS COMPANY, OF MANSFIELD, OHIO, A CORPORATION OF NEW JERSEYCONNECTION FOR HIGH VOLTAGE LINES Application filed January 21, 1928.

This invention relates to high potential connections and has for itsobject the provision of a connection with a high voltage line which willbe simple and inexpensive and by means of which energy may be derivedfrom the line for purposes of synchronizing, determination of voltage,derivatlon of power, or other purposes where the amount of energyrequired is not excessive and where expensive transformer mechanism isnot desirable. Other objects andadvantages will appear'from thefollowing description.

The invention is exemplified in the comb nation and arrangement of partsshown n the accompanying drawings and described in the followingspecification, and 1t 1s more particularly pointed out in the appendedclaims.

In the drawings- Figure 1 is a partly diagrammatic elevation showingcondensers and connecting c rcuits for one embodiment of the present1nvention.

Figure 2 shows a series of curves illustrating the effects of onefeature of the invention.

Figure 3 is a circuit diagram showing a slightly modified arrangement ofthe invention.

Fig. 4 is a circuit diagram showing a further modification of theinvention.

Fig. 5 is a diagram of the circuit used in obtaining the curves of Fig.2.

In connecting very high voltage lines it is frequently desirable to knowthe voltage on the lines at the time they are connected and to be ableto synchronize the two different lines. In general this has been carriedout in two different ways. One has been by means of a condenser which weshall call the electrostatic method. In general. the condenser for thiswork has been made up of high voltage insulators whose capacity andenergy is "ery much limited. The more common method has been to step thevoltage down from the line by means of a potential transformer,potential transformers being used on the respective lines to besynchronized. The phase relation of the two lines can then be Serial No.248,471.

determined by a synchronoscope or by means of lights in a manner wellknown in the art. Still another method of synchronizing has been to usea capacity or condenser coupling such as that afforded by a bushinginsulator. Owing to the fact that the energy available in this way isvery much limited, the energy has been amplified by the use of one ofthe well known Vacuum tubes or kenetrons. IVhile this method makes itPOSSibl': to provide ample energy, it is necessary in most cases toprovide special bushings and considerable auxiliary equipment isnecessary to provide sufficient energy to operate the synchronoscopes orother equipment, which tends to make the system complicated and robs itof some of its reliability.

In the improved method of supplying sufficient energy for thedetermination of voltage or for synchronizing according to the presentinvention, ample energy is provided so that the indication of voltagemay be shown at a considerable distance from the electrostatic coupling.As the equipment is simple and rugged, it lends itself readily toinstallations in the open. It may be applied to the ordinarysynchronoscopes without additional amplifying apparatus, even though thesynchronizing indicator is located at a very considerable distance fromthe high voltage lines to be synchronized.

An installation is shown connected to a single phase only. It isevident, however, that connections may be made between more than onephase, if desired. If the phase rotation is not correct, it is evident,however, to anyone familiar with the art that all that is required is todetermine the relation of a corresponding phase on each line.

Fig. 1 shows one form of the improved method of supplying energy forindicating voltage or for synchronizing. The same arrangement ofcondensers and transformers may be used for tapping a high voltage linewhere power is desired in limited quantities for various purposeswithout going to the expense of providing a high voltage transformer,which would be very expensive.

The conductors of the two lines to be synchronized are shown by and 11respectively. A condenser composed of elements 12' is connectedelectrically to the power condiuctor through fuse 13, Fig. 3, andresistance 14. The condenser may be of any desired capacity and made ofenough units in series to provide a factor of safety sufiicient towithstand line voltage. a

One difference between this scheme and the other electrostatic schemesheretofore used is the use of a larger coupling condenser and atransformer placed between the coupling condenser and ground. While ited by the voltage, and the capacity of the line to is possible simply touse a larger coupling condenser, the voltage placed on the windingrunning from the condenser will be limitcapacity of the condenser,the'line ground. If the line to ground is opened, a very high voltagewill exist and may endanger life. For this reason it has not beenfeasible to use coupling condensers of larger size so that synchronizingcould be carried on at a distance. Another disadvantage in using largecondensers without a transformer is that the voltage to ground may varyconsiderably depending upon the length of .line. In operation thecurrent passes through the condenser 12, flows through the primarywinding 15, energizing the magnetic core 16 of the transformer andsecondary winding 17. After passing through the winding 15 the currentmay be carried through a primary winding 18 of another transformer whichwill energize its core 19 and secondary winding 20. The current thenpasses to ground.

Duringlightning storms, switching surges, or abnormal voltages on thetransmission line, it is evident that the condensers will permit thepassage of a very large current at a high frequency. Owing to thereactive drop in the transformers, the transformer 'might be broken downby the drop in potential unless protected in some way. Several methodsof providing this protection may be used, either singly or collectively,depending upon the conditions existing in the particular installation.Where the resistance 14 may be large such as from 50,000 to 500,000ohms, the condensers will still pass enough current at normal frequencyto give the desired indieatiombut at the high frequencies the dropimpotential instead of being largely across the condensers, will takeplace over the resistance and thereby afford protection to thetransformer, providing, however, that 'a limiting or discharge gap 21 isprovided or a condenser 22 in multiple with the trans former is used.

Since the regulation of a circuit taking power from a condenser is' verypoor owing to the well known electrical laws, this together with thedangerous voltage on the low side of the condenser when the circuit onthe low side is open, tends to limit its use as explained previously. Tooffset this difficulty, the transformer having primary or high voltagewinding 15 and core 16 is used giving an inductive reactance in serieswith the.

wound on the core 16 and a leakage path for the magnetic flux is formedby a tongue 38 having a short air gap between it and the opposite leg ofthecore. This produces a transformer having a high inductive reactanceand in which the magnetic flux will practically all flow through thecore of the secondary at no load but in which there willbeincreasingleakage as the load increases. The curves shown in Fig. 2 werederived from the circuit arrangement shown in Fig. 5 in which atransformer having a high leakage between windings was employed. It willbe seen that when a voltage of 30 k. v. was impressed on the conductorline, the voltage remained approximately constant for 10 to 100 voltamperes on the secondary. By operating in this part of the curve, amplepower can be obtained for synchronizing, determination of voltage orother purposes even through a circuit extending to a point quite remotefrom the transformer. way, it is possible to vary the duty imposed onthe winding 17 over an appreciable range without seriously affecting thevoltage.

It is evident from the above considerations that this method of usingcondensers and transformers provides an easy means of tapping very highvoltage lines inexpensively where the amount of power required is notvery great. By providing taps, either on the high voltage winding or thelow voltage winding of the transformer, it is possible to make theequipment applicable for a wide range of voltage conditions on the line,even though the condenser remainsv approximately the same.

It is evident that the proper relation may be setup by changing both thecondenser and high voltage transformer winding to set up the desiredsaturation in the transformer core.

Where lights are used to synchronize, it is possible to have anindication of voltage on each circuit in addition to the lamps used insynchronizing. There is sufficient energy so that ordinary 110 voltlamps of fair candle power may be used for the synchronizing and With atransformer made in this the synchronizing may be accomplished by eitherthe bright or dark method as preferred.

Since the current flowing through a condenser is directly proportionalto the voltage, frequency, and electrostatic capacity of the condenser,it may be used in conjunction with a suitable current measuringinstrument for the indication of voltage, as in most systems thefrequency is held within very close limits for this purpose, but inorder to do this, it

is necessary to protect the instrument from surges as the drop involtage across the instrument during the disturbance may readily .breakdown the winding and very elaborate means for protection are provided asthe instrument must be fairly sensitive owing to the small currentinvolved. If, however, a transformer having a winding 18 and a core 19is used and so proportioned that the volt ampere output is proportionalto the current flowing through the primary winding 18, the voltage onthe line may be indicated by a suitableinstrument 23 inthe secondarycircuit 20 of this transformer. lVhere'the instrument 23 is a lowresistance instrument, the windings 18 and 20 together with the core 19form a current transformer which is used to indicate voltage. This orthe synchronizing circuit may be used to operate relays for the controlof the system if so desired.

It is evident that the transformer scheme thus avoid the cost of a highvoltage condenser. This is quite important where a carrier currentsystem Is already installed and,

it is desired to utilize the coupling condenser as outlined above. Inits application to a carrier current coupling condenser, the transformermay be attached in one of two ways.

lVhere a transformer is attached to a carriercurrent coupling condenseras shown in Fig. 1, the carrier current coupling is attached to thebottom of the stack of condensers 12 which is insulated from the ground.A limiting gap 32 is used between the ground side of the couplingcondenser and ground. Since the carrier current lead 30 has a lowimpedance to ground at normal frequency, the ground side of thecondenser may be regarded as at ground potential under normal frequencyconditions. If the primary side of the transformer is tapped into thecondenser at 33 and the other side attached to ground, it will be seenthat the transformer will be energized by the voltage at this point,part of the current flowing through the transformer winding to groundand part through the lower portion of the condenser. \Vhere the voltageon the condenser is high, the transformer tendsto relieve the lowerportion of the condenser from duty unless the transformer hasconsiderable reactance. The impedance of the transformer circuit,however, prevents the high frequency carrier current from be ingby-passed to ground. Where it is desired to limit the current throughthe transformer, a condenser 34 may be placed between the point 33 andthe end of the transformer winding 15. It is evident that even where hecondenser 34 is used, the major portion of the coupling condenser isfurnished by the condenser only for the carrier current system. Thismethod therefore provides an inexpensive method for coupling even to avery high voltage line such as a 220,000 volt line where condensers arealready in the circuit. The method, even where the condensers are notalready in use for carrier current, is probably much cheaper and farmore reliable than that which may be provided by a potential transformerinstallation.

It is evident that the scheme disclosed makes it possible to providelight or power at various points along a transmission line at relativelysmall expense. By providing suitable synchronizin switches, switchingstations may be suita ly equipped, even though there are not theordinary facilities presentusually found in a station. Where this systemis used, all that is necessary to connect two high potential lines is toprovide suitable means for closing the two circuits when synchronized,which may be carried out by a suitable air break switch or oil circuitbreaker.

The secondaries of the transformers connected with the two lines to besynchronized are connected by conductors 24 provided with a switch 25and lights 26 or other means for indicating when the lines are insynchronism. Lights 27 may be provided to indicate when the transformersare energized.

In Fig. 4 the circuit is shown for connecting the secondary windings 17with a synchronoscope 28. The synchronoscope 28 18 connected withcontact sockets 29 provided with starting-and running plugs 36 and 37for connecting the synchronoscope with the secondary windings of thetransformers for either starting or running connection.

I claim 1. Means for Withdrawing energy from a high voltage alternatingcurrent transmission line comprising a condenser having one terminalconnected with said line, a resistance in series with said condenser, atransformer having its primary winding in series with said condenser,current receiving means in circuit with the secondary of saidtransformer, and a condenser in parallel with the primary winding ofsaid transformer.

2. The combination with a high voltage transmission line having carriercurrent apparatus connected therewith, comprising condenser units inseries, of an indicating circuit connected with said condensers betweenunits thereof, said indicating circuit including a condenser and atransformer, the priformer,

set including a number of series at a point closer mary winding of saidtransformer being in series with said condenser and an indicator 0 a lin series with the secondary winding of said transformer,'saidtransformer having a low reluctance leakage path between the windingsthereof. 3. The combination with a high potential transmission line, ofa condenser having one terminal thereof electrically connected with saidtransmission line, said condenser-comprisingsets oflcondenser units inseries,

condenser units in parallel, carrier current apparatus connected withsaid condenser at one point thereof, a transformer connected with saidcondenser at a different point thereof and separated from said carriercurrent connection by a set of condenser units, a condenser in serieswith said ,transformer and in parallel with said last named set ofcondenser units, and an indicating instrument in the secondary circuitof said transformer. 1

4. Means for diverting energy from a high oltage alternating currenttransmission line comprising a condenser having a plurality of condenserunits in series, one terminal of said series being connected with saidtransmission line and the other terminal of said series being grounded,a transformer having one terminal of its primary winding connected tosaid condenser series at a point in termediate the ends of said series,an electrical translating device connected to said to the grounded endthereof than the connection with said transand current receiving meansin series with the secondary of said transformer. 5. Means for divertingenergy from a high voltage alternating current transmission linecomprising a condenser having a plurality of condenser units in series,one terminal of said series being connected with said transmission lineand the other terminal of said series being connected t rough anelectrical translating device to ground, a transformer having oneterminal of its'primary winding connected to said condenser series at apoint intermediate the ends of said series, current receiving meansconnected with the secondary winding of said transformer, means inparallel with the primary of said transformer for limiting the voltageimpressed on said primary, and a condenser unit electrically connectedin series with said primary and between said primary and its point ofconnection with said condenser series to prevent said point ofconnection in said series from being grounded when said voltage limitingmeans is short-circuited. v

' 6. Means for diverting energy from a high voltage alternating currenttransmission line .coniprising'a condenser having a plurality forcondenser sections in series, each section comprising a plurality ofunits in parallel,

each

one terminal of said series being connected with said transmission lineand the other terminal of i said series being grounded through anelectrical translating device, a transformer having one terminal of itsprimary windingconnected to said condenser series at a pointintermediate the ends of said series, a current receiving meansconnected with the secondary of said transformer, an arcing gap inparallel with the primary of said transformer for limiting the voltageimpressed on said primary, and a condenser unit electrically connectedin series with said primary and between said primary and its point ofconnection with said condenser series to prevent said point ofconnection in said condenser series from being grounded when said arcinggap is short-circuited by an elec= trical discharge.

7. Means for withdrawing energy from a high voltage alternating currenttransmission line comprising a condenser having one terminal connectedwith said transmission line and the other terminal thereof grounded,said condenser comprising a plurality of main condenser sections inseries, a supplemental condenser section in series with a part of saidmain'condenser sections adjacent the transmission line and in parallelwith a main condenser section adjacent the grounded end of said series,a transformer mary winding in series with said supplemental condensersection and electrically connectedbetween said supplemental condensersection and ground, and current receiving means in circuit with thesecondary of said transformer.

8. The combination with a high potential transmission line, of acondenser stack comprising a plurality of sections in'series having oneterminal thereof connected with said transmission line, carrier currentapparatus connected between the other terminal of said condenser stackand ground, a branch circuit in series with a portion of said condenserstack and in parallel with another portion of said stack, said branchcircuit comprising a condenser unit connected with said condenser stackat a point intermediate the ends thereof, and a transformer having itsprimary winding in series with said condenser unit.

9. A condenser coupling comprising a plurality of condenser sections inseries, one terminal of said series being connected with a highpotential transmission line, a carrier current circuit connected betweenthe other terminal of said series and ground, and a transformer circuitin series with certain of said condenser sections next adjacent saidtransmission line and in parallelwith certain of said sections adjacentthe ground connection of said stack, said transformer circuit comprisinga condenser unit, a trans- Ill ARTHUR O. AUSTIN.

